quality control
Product testing facilities and laboratory are located at the Test Centre in Great Yarmouth. The majority of the testing capacity is dedicated to monitoring product performance and specifications and involves the sample testing of products from actual production lots.
Specific equipment used includes the following:
QUV - Accelerated Weathering Tester
Conforms with:
- ASTM D5208-91 - Standard Practice for operating fluorescent, UV, and condensation apparatus for exposure of photodegradable plastics. Heat ageing testing to prove the thermal degradation alone is conducted in accordance with ASTM D5510-94
- ISO 4892 - Methods of exposure to laboratory light sources - part 3: fluorescent UV lamps. DIN 53 384 - Testing of plastics, Artificial Weathering and exposure to artificial light.
The Q-Panel weathering test equipment is the most widely used equipment for this purpose in the world. In a few days or weeks the QUV can reproduce the damage that occurs over months or years outdoors by reproducing the effects of sunlight, rain and dew. The QUV tests materials by exposing them to alternating cycles of light and moisture at controlled, elevated, temperatures. It simulates the effect of sunlight with fluorescent ultraviolet (UV) lamps while it simulates rain and dew with condensing humidity or water spray.
Samples are exposed for different time periods and at each fixed interval the physical properties of the film, and the mechanical characteristics of the polymeric material, are tested - usually against control samples. The UVA-340 lamp gives an excellent simulation of sunlight in the critical short wavelength region from 365 nm down to the solar cut-off of 295 nm.
Irradiance is the rate at which light energy falls on a surface. Changes in light intensity (i.e. brightness) may affect the speed of material deterioration. Changes in light wavelength (i.e. spectral power distribution) may affect both speed and type of material degradation. For example, an irradiance of 0.68 W/m2 / nm@340 nm is a good match with noon, summer sunlight. The level of irradiance in the Q-Panel QUV equipment is controlled through a Solar Eye Irradiance Control which monitors the UV intensity via four sensors at the sample plane.
Photochemical reactions are not usually temperature sensitive. However, the rate of any subsequent reactions is temperature dependent. The rate of these reactions increases with increasing temperature. Consequently it is important to have control of temperature during UV exposure. Further, it is important to match the accelerated test's temperature with the maximum experienced by the material in direct sunlight. In the QUV the temperature can be set at any point from 50°C to 80°C (122°F to 176°F) depending on irradiance level and ambient room temperature. UV temperature is regulated by a forced air system controlled by the microprocessor controller giving excellent temperature uniformity.
AMETEK Lloyd Instruments LRXPlus Series - Tensile Tester
Conforms with:
Exceeds the requirements of BS EN ISO 7500: 1999. Class 0.5 or Class1, ASTM E4, DIN 51221
This equipment is designed for material testing applications with capacities up to 5kN (1100 lbf). It features a single column with a crosshead travel range of 735mm (29 inches).
Other features:
- Crosshead speed: 0.01 to 1020 mm/min
- Speed accuracy: <0.2%
- Load resolution <0.005% of load cell used
- Extension resolution: <0.1 micron
- Data sampling rate 1000hz
Messemer Buchel - Tear Tester
Conforms with:
TAPPI T-414, ASTM D1922 and D1424, ISO 1974, CPPA D.9, AS/NZ 1301.400S, BS 4468 and SCAN P-11
Tear Testing determines the force required to continue the tearing of an initial cut in sheet materials.
Davenport - Melt Flow Indexer
Conforms with:
ISO 1133 and ASTM methods A and B
Used to determine the melt flow rate of a polymer by extruding it in a molten state through a calibrated die using a reference weight. The machine calculates MFI, MFR, MVR and Melt Density/Viscosity.
Other features:
- Temperature range: 40°C to 400°C
- Temperature controller: <0.1°C accuracy.